如何将这个表格单元格放在一行中？

Question

我如何将单个细胞集中在tr内，是否有一种我不知道的属性？所以，我希望无论在上方还是下方添加多少个单元格，单个单元格都会居中，如果可能的话......？这是在电子邮件模板的上下文中。

＆＃13;

＆＃13;

td {
  border: 1px solid blue;
  padding: 50px;  
}

.center {
  padding: 0;
}

＆＃13;

<table id="main">
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table>
        <tr>
          <td class="center">center me please</td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
</table>

＆＃13;

＆＃13;

＆＃13;

Answer 1

只需将align="center"添加到您想要成为中心的table

td {
  border: 1px solid blue;
  padding: 50px;  
}

.center {
  padding: 0;
}

<table id="main">
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table align="center">
        <tr>
          <td class="center">center me please</td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
</table>

Answer 2

简单应用内表的左右margin: auto

td {
  border: 1px solid blue;
  padding: 50px;  
}

.center {
  padding: 0;
}

/*Apply left and right margin: auto of the inner table*/
#main table {
  margin:auto;
}

<table id="main">
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table>
        <tr>
          <td class="center">center me please</td>
        </tr>
      </table>
    </td>
  </tr>
  <tr>
    <td>
      <table>
        <tr>
          <td></td>
          <td></td>
        </tr>
      </table>
    </td>
  </tr>
</table>